Thanks in advance for the many quick responses.
I see it similarly to your assessments. I will definitely contact the building authority to clarify the fire protection regulations.
Access via a neighboring property would only be possible by tearing down a wall and would take away their space for a bicycle parking spot, so even for money it is very unlikely.
The neighboring houses all actually have somewhat wider driveways (3m+). I have also read this regulation with a minimum driveway size of 3x3.5m, but I understood it to mean that the driveway only has to have these dimensions if it is more than 50m away from the street.
For me personally, it would be okay if the driveway were only passable by a very narrow vehicle, since it would also be very difficult to widen the driveway. This would be a limitation I would accept, since the price corresponds rather to the price for a multi-family house without land and additional building possibilities, and I could finance the new house very well this way.
Does anyone have experience with how far the arms of normal construction cranes reach, which set up the parts for a prefab house? Is setting up under these conditions (erecting over 2.5 stories + gable roof and about 40m into the property) even possible with a reasonably affordable crane?
I realize this is obviously not the easiest way to build a house. But the prices in our area only allow for creative solutions.
did you also have to deliver parts over another house for your building in the second row? If yes, how did that work, what were the additional costs, ...